View Full Version : Topside seams

04-27-2010, 05:59 PM
What is recommended for deck seams. I have mahogany plank on white oak. The deck will be painted. What does everyone think is the best product. Thanks Bill.

Lew Barrett
04-27-2010, 08:05 PM
I presume you mean deck seams and not topsides...these are two different topics. But I'll go with the body of your text, not the title. This has been covered a great deal, so check the forum for deck seams or paying deck seams. TDS seems to be the product du jour here. I used it two years ago, very good so far.

There is a lot to say about this subject, including how to apply and what coatings if any will be compatible. In addition, the choice of TDS is by no means universally agreed upon but my experience with it has been good. They say it won't accept varnish, but that has not been my experience.

C. Ross
04-27-2010, 08:15 PM
Lew, how does it compare to Interlux? My limited experience with Interlux (african mahogany on oak) was really good.

Lew Barrett
04-28-2010, 10:42 AM

Unless Interlux has sneaked a deck seam compound into the market while I wasn't looking, it and TDS are not for the same job.

I assume you are talking about one of two Interlux oil based seam compounds; "Underwater Seam Compound" or "Interlux Seam Compound." Those are designed to fill the seams between either topsides or bottom planks on a carvel build. In the case of the bottom seam compound it is a variation on the Dolphinite theme. I have used it and it is OK, does the job for bottom seams. I prefer the Pettit version (much, much harder to find) because it trowels in easier, but both "seem" to do the job on the bottom.

I have not used Interlux's topside seam compound, couldn't say how it performs. I have a home brew for topsides.

TDS is another league of product as it's strictly intended for deck seams. Here on the forum I think the discussion has evolved into two camps (with off-branching sects and schisms) . The Jeffries Marine Glue Camp and the TDS camp. I will let Jay Greer advocate for Jeffries, but my 2 cents on it is that for finished yacht decks it leaves something to be desired; not necessarily by way of performance per se, but rather because of the way it finishes, or doesn't. For me, that leaves TDS. I have tried Boatlife; beneath contempt for deck seams. I suspect Sikaflex doesn't do much better.
Detco is somewhat better performing than either of those (used it and it is "OK") but TDS seems to have nailed the trick of adhesion, flexibility and long wear for deck seams on a boat like mine.

This is a combative, contentious and potentially very long winded discussion between adherents (hehe punny all over!) of different deck seam compounds.
But in this task as much as any other repair you make on a boat with laid decks, choice of materials and technique seem to be critical for ongoing happiness. Each owner should do a lot of research on this topic to satisfy himself he or she made the best choice for the circumstances.

Again, a pretty contentious topic. I can say that as pretty as they are, laid decks sort of suck. I guess it's within the nature of a vehicle built from little sticks that must take the forces of sea, wind and weather that keeping the water out is always a challenge.

04-28-2010, 01:39 PM
Again, a pretty contentious topic. I can say that as pretty as they are, laid decks sort of suck. I guess it's within the nature of a vehicle built from little sticks that must take the forces of sea, wind and weather that keeping the water out is always a challenge.

No, no, no.... Laid decks are BEAUTIFUL and WONDERFUL....

...as a cosmetic facia over a REAL deck, framed in hardwood, skinned in good marine ply, fastened with silicon bronze screws, and reinforced with glass tape and epoxy ;-)

Lew Barrett
04-28-2010, 02:25 PM
We agree then!

04-28-2010, 02:35 PM
We agree then!

Damn skippy.

It bugs me that many people don't understand their decks are a MAJOR component of the strength of their wooden boats.

It's not like an aluminum hulled skiff where all the strength is in the origami of the hull and the "ribs", and a deck is a cosmetic, or at best functional for fishing, afterthought.

Unless you've got full bulkheads (and most boats in the class we play with don't) without a solid deck structure, especially in the foredeck; any kind of rough seas will flex your hull sides above the chine, until they spring themselves.

Lew Barrett
04-28-2010, 02:48 PM
Agreed again! Hope that's not too skippy for you. :D

Lew Barrett
04-28-2010, 06:50 PM
Taking note of the fact that the decks will be painted, it would be interesting to see how an oil based compound might work. You don't often see laid decks painted, at least I don't.
I'd be inclined to experiment with white lead mixed into the seam compound.
I have had good luck with that on topsides. My own invention (and I'm not very inventive) or at least I haven't heard of anybody on the forum but me trying it. White lead putty was an option seventy years ago in this application, I've been told

04-28-2010, 08:25 PM
Our decks are cedar,caulked with cotton and payed with BoatLife polysulfide and painted. At 26 yrs. old there are no leaks,dry and comfy, we keep a coat of thinned paint on the deck,plenty of salt water and winter over in the water.